Colombia has approximately 379,954 hectares of mangrove forests distributed along the Pacific Ocean and the Caribbean Sea coasts. Such forests are experiencing the highest annual rate of loss recorded in South America and, in the last three decades, approximately 40,000 hectares have been greatly affected by natural and, especially, human impacts. This study determined, by the use of Landsat multispectral satellite images, the evolution of three mangrove forests located in the Colombian Caribbean Sea: Malloquín, Totumo, and La Virgen swamps. Mangrove forest at Mallorquín Swamp recorded a loss of 15 ha in the period of 1985–2018, associated with alterations in forest hydrology, illegal logging, urban growth, and coastal erosion. Totumo Swamp lost 301 ha in the period 1985–2018 associated with changes in hydrological conditions, illegal logging, and increased agricultural and livestock uses. La Virgen Swamp presented a loss of 31 ha in the period of 2013–2018 that was linked to the construction of a roadway, alterations of hydrological conditions, illegal logging, and soil urbanization, mainly for tourist purposes. Although Colombian legislation has made efforts to protect mangrove ecosystems, human activities are the main cause of mangrove degradation, and thus it is mandatory for the local population to understand the value of the ecosystem services provided by mangroves.

Litter abundance and typology were investigated at different beaches and mangrove forests at nine sites on the Colombian Caribbean and Pacific coasts. Average litter abundance on the Caribbean Sea beaches (1.42 items/m²–12.21 g/m²) and in mangrove forests (1.29 items/m²–28.72 g/m²) were greater than that of the Pacific Ocean beaches (0 items/m²–0 g/m²) and mangrove forests (1.13 items/m²–79.41 g/m²). The most abundant litter material was plastic, which represented 93.61% of the total litter content. According to the Clean Coast Index, the sites analyzed in the Caribbean Sea were “Moderate” to “Extremely Dirty”, while those in the Pacific Ocean were “Clean” to “Moderate Dirty”. The Magdalena River is considered the main source of litter on the Caribbean Sea coast, while on the Pacific Ocean coast, litter is essentially associated with the mismanagement of solid wastes. This study constitutes a baseline on the litter content of beaches and mangrove forests, and is useful for establishing sound strategies for their protection, restoration and conservation.

Interaction of Anthropic interventions (rigid structures) with coasts is an essential aspect for understanding their geomorphic evolution and incorporating these data into adequate coastal management. This study analyses the short and long-term behavior (1985 to 2019) of shoreline at Santa Marta Bay (Caribbean - Colombia) and their relationship with coastal protection structures. The shoreline variations were analyzed through aerial photographs and satellite images using DSAS tools. The short-term assessment showed initial intense 1985–1991 erosion, with an average retreat speed rate of − 1.6 m·y^− 1. It changed gradually since 2003, due to the construction of rigid structures and beach nourishment, decreasing shoreline retreat and even a progradation rate of 0.2 m·y^− 1 was observed. The 2009–2019 period, despite recording a positive average value, exhibited a high percentage of erosion profiles. Therefore, in a decadal or long-term analysis (1985–2019), despite engineering works present positive results in the short term, new interventions are required. The coastal erosion is not uniform along the shoreline, because the area is a closed bay with small sediment inputs, the variations in erosion and accretion rates change with human intervention and the installation of new structures. Therefore, quantifying the scale and rate of shoreline changes and correlating them with anthropogenic structures is an essential step in assessing shoreline vulnerability.

The great importance of mangroves’ forest is linked to their capacity of resilience against natural and human impacts, this way playing a determinant function in the adaptation to climatic change related processes. At global scale, mangroves’ forests cover an area of 150,000 km2, 11% (≈16,500 km2) of them being located along the Pacific and Caribbean coasts of South America. About 70 species of mangroves exist around the World with 10 observed in South America, among them the most relevant are: Rhizophora mangle, Avicennia germinans, Laguncularia racemosa and Conocarpus erectus. Concerning mangroves’ cover loss, at global scale, an annual rate of 0.16% was observed between 2000 and 2012 with lower rates recorded in South America respect to Asia, Africa, North and Central America. This paper analyses the main effects of natural and human impacts on mangroves’ forests by means of examples from South America and several other countries. Concerning natural impacts special attention was devoted to: i) constant and ii) specific erosion processes (related to storms and tropical cyclones), both of them essentially affect Rizophora mangle since this specie occurs at the shoreline meanwhile strong winds recorded during hurricanes (with a category > 3 of the Saffir-Simpson scale) especially affects R. mangle and A. germinans, and iii) the effects of climatic phenomena such as “El Niño” and “La Niña” that produce variations in soil salinity that determinates the establishment and growth of a mangrove’s specie or an other. Concerning human impacts special attention was paid to illegal logging that, in the Northern Caribbean of Colombian coast essentially affectes L. racemosa, which wood is used by local population to build up cabins on the beaches for tourist purposes. Keywords: Coastal erosion, Hurricane, El Niño, Deforestation, Salinity.

Mangrove forests provide essential ecosystem services but are increasingly threatened by anthropogenic pressures and climate-related disturbances. Effective and accessible tools for assessing mangrove ecosystem condition are therefore needed to soundly support their conservation and management. This study adapted the “Coastal Health” framework originally proposed for assessing coastal ecosystems health to evaluate the health status of mangrove forests along the Caribbean coast of Colombia. Using freely available high-resolution imagery from Google Earth Pro 7.3, complemented by field observations, technical reports, and unpublished literature, 56 mangrove sites distributed across eight coastal departments were assessed according to their ecological integrity, hydrological connectivity, sediment dynamics, freshwater and marine inputs, mangrove species condition, and their potential for landward and seaward migration. The results showed that 54% of the evaluated sites were classified as being in “Good Health”, while 2% were categorized as “Health Warning”, 3% as “Surface Wounds”, 14% as “Minor Injury”, 25% as “Major Injury”, and 2% as “Deceased”. Mangroves in good condition were generally associated with protected areas, river mouths, estuaries, and relatively isolated coastal systems, whereas degraded ecosystems were affected by urban expansion, tourism infrastructure, hydrological alterations, coastal engineering works, and reduced freshwater inputs. The proposed methodology proved to be a simple, low-cost, and easily replicable tool for large-scale mangrove health assessment. It provides valuable information for prioritizing conservation and restoration actions and can be adapted to support mangrove monitoring and ecosystem-based coastal management in other regions worldwide.